1. Field of the Invention
The invention relates generally to firearms and, more particularly, to muzzle-loading firearms which require a breech plug.
2. History of the Prior Art
Early in 1968, President Johnson signed into law the Omnibus Crime Control Bill, which included sundry curbs on handguns, including a ban on the interstate mail-order sale thereof. However, the President did not think that ban went far enough, and so he proposed new gun legislation targeting shotguns and rifles. After prolonged and heated debate, Congress finally enacted the strongest gun control legislation in the nation's history on October 22 of that year. As finally approved, the legislation: outlawed the mail-order sales of all rifles, shotguns, and ammunition, except between licensed dealers, manufacturers, and gun collectors; banned the sale of rifles, shotguns, and handguns to persons under 21 years of age; and banned direct sales of guns to out-of-state residents unless the state involved specifically authorized its citizens to buy guns in adjoining states. Muzzleloading, black-powder firearms, though, were exempted from most of the restrictive legislation.
During the past three decades, muzzleloading firearms have enjoyed a strong resurgence in popularity. Certainly, the federal exemptions from the ban on interstate mail order sales have helped. In addition, because black-powder firearms have significantly less range and are generally less accurate than smokeless, breech-loading firearms, most states have established special seasons for muzzleloader hunting that are more favorable than those allotted to breechloader hunters. However, the most significant factor in the growing popularity of muzzleloader firearms is almost certainly the challenge associated with the use of a single shot rifle during the hunt. Muzzle-loader hunters style themselves as an elite group. A single shot with a weapon of less range, at a quarry likely made wary by other hunters who came before you, has almost irresistible appeal for many. The allure of muzzleloading hunting is the same as that afforded by flyfishing: the greater the challenge, the greater the satisfaction. Today, there are two basic types of muzzleloaders used for hunting: primitive and in-line. Both types require the introduction of a measured powder charge into the gunbarrel, and the ramming of a slug or ball down on top of the charge to load the gun.
Primitive muzzleloaders generally use either a flintlock or a caplock ignition system. The flintlock, popular from the time of the Revolutionary War through the early 1800s, is the more primitive technology. The hammer of the gun holds a piece of flint wrapped in fine leather. Below the hammer is a swinging metal plate known as the frizzen. Below the frizzen is the pan, into which the shooter pours a small amount of fine black powder. Pulling the trigger releases the hammer, which strikes the frizzen, which then folds back, thereby showering the powder in the pan with sparks. The powder ignites, shooting a tongue of flame into the barrel of the gun via a small port. This port is an ignition aperture, and directs hot ignition gasses into the barrel. The powder charge in the barrel ignites, expelling the ball or slug that has been rammed down the barrel. The foregoing process is as cumbersome as it sounds. Ignition is neither instantaneous, nor certain. A full second or more may elapse between pulling the trigger and ignition of the measured charge. Flintlock shooters must remain steady for that period.
The caplock ignition system, though the more modern of the primitive technologies, still relies on a side hammer design and the funneling of a flame into a port in the barrel. However, ignition is accomplished through a small nipple seated under the hammer. A copper percussion cap filled with a small amount of priming compound is placed atop the nipple. When the hammer falls, the cap shoots a tiny spurt of hot flame through the nipple and into the port in the barrel, thereby igniting the powder inside and expelling the slug or ball from the barrel. Ignition of the loaded charge is much more direct and rapid than with the flintlock.
The special muzzleloader hunting seasons were originally established for the intended use of primitive percussion or flintlock rifles or shotguns, using black powder and open metal sights. These types of guns have specific limitations. Loading such a gun is considerably more cumbersome and time-consuming than loading cartridges into a breechloader. Thus, the hunter may get only one shot at his game, so he'd better make it count. This necessitates getting close to the quarry, learning to shoot well with open sights, and keeping the powder dry in inclement weather.
An in-line ignition muzzleloader, on the other hand, utilizes a plunger-type hammer, which strikes a nipple centered at the rear of the breech plug. An in-line ignition is quick and reliable because the fire from the cap travels a straight, short distance into the powder charge rather than bouncing around a corner as it does in a side hammer design. In all other respects, an in-line rifle loads and shoots identically to a traditional side hammer percussion muzzleloader. In-line rifles are nothing new. Some flintlocks used in-line ignition as far back as the 1700s, although the lack of sufficiently powerful springs to drive the in-line hammers probably kept them from supplanting side-hammer rifles. In the early 1970s and 1980s a couple of rifles, most notably the Michigan Arms Wolverine, featured an in-line ignition. The Wolverine, however, had a long, heavy octagonal barrel and never caught on with shooters.
Tony Knight, a gunsmith from rural Lancaster, Mo., is generally credited with building the first modern, lightweight, in-line blackpowder rifle. Knight was no traditionalist, and figured that any hunting rifle should be equipped with a tapered 22-inch barrel. Starting with a Numrich Arms barrel, Knight added a removable, friction-securable, threaded breech plug that simplified cleaning and allowed hunters to push an unfired charge out the breech instead of having to fire the rifle or pulling the ball back out of the barrel to unload it. He also incorporated Remington sights, a handmade trigger, and a stock carved from a piece of walnut cut from a tree on his farm. Knight's first in-line design, which he christened MK-85, is considered a milestone in muzzleloader technology.
Knight's new rifle set the standard for in-line models subsequently manufactured by hundreds of competitors, both large and small. The in-line rifle business is booming. One can now purchase a gun that looks and operates very much like a modern sporting rifle. In essence, it is a modern single-shot rifle that is loaded with a ramrod. Many in-line shooters use pelletized powder, such as those produced by Pyrodex®, that can be dropped into the barrel in 50-grain increments, and saboted bullets that are constructed much like a high-powered rifle bullet, but with a plastic sleeve which allows them to be more easily rammed down the barrel. With a shotgun primer, a #11 primer cap, a musket cap, or a primer adapted from a center-fire cartridge securable in the breech to ignite the propellent charge, rain and high humidity are much less problematic, especially if the firearm is fabricated from stainless steel. Many of these modern rifles, which may be fitted with scopes and other optical sights, are capable of groupings of one inch or less at a range of 100 yards.
The use of an in-line rifle, no matter how sophisticated the features, still means single-shot, front-loading, no-mistakes hunting. An in-line hunter accepts the same challenge of placing one well-aimed shot at relatively close range. Granted, a properly loaded, scoped in-line enjoys a big advantage in effective range over an open-sighted rifle shooting round-balls. In a sense, the in-line rifle is to blackpowder what the compound bow is to archery: easier to shoot and harder-hitting than traditional gear, yet subject to the same underlying limitations.
The present invention involves a new type of breech plug. Breech plugs are used to stopper the barrel at the breech end thereof. All muzzleloading firearms do not have removable breech plugs. Early muzzleloading cannon barrels, for example, had the breech plug cast unitary with the barrel. On primitive muzzleloader rifles and pistols, the bore of the barrel does not extend to the breech. Because the combustion of black powder forms highly corrosive deposits in the barrel, frequent cleaning of muzzleloader firearms is essential. For a muzzleloader having no breech plug, cleaning the barrel and extracting an unfired charge can be quite a chore. A removable breech plug greatly simplifies those tasks, as cleaning of the barrel is most easily effected by removing the plug and running a cleaning rod through the barrel from the muzzle into the breech. One of the problems associated with conventional threaded breech plugs is that removal of the plug requires the use of a wrench or other special tool. Threaded breech plugs typically have either a polygonal socket or shank which can be engaged with a wrench. For socket-type plugs, an appropriately-sized square or hexagonal Allen wrench is used; for shank type plugs, an appropriately-sized socket, box-end or open-end wrench is used. On an in-line rifle, the firing plunger assembly can be disassembled so that the plug may be accessed directly using an extension inserted through the end of the receiver. Although removal of the firing plunger requires the expenditure of additional time and effort, it facilitates removal of the breech plug. Thus, no matter which method is used, removal of a conventional threaded breech plug is, at the very least, a nuisance.
What is needed is a new type of breech plug that may be quickly removed without tools.